Setup
Remote into the Minicomputer
Setup Tailscale (a piKVM)
Priya Jakhar needs to send you an invitation to your email
Once the invite has been accepted, create an account with your github account
Follow the on-screen instructions to setup tailscale
Connecting to the Minicomputer
Once you’re tailscale account is setup, go to your dashboard and you should see your account and the benchbot account.
The benchbot account needs to be “connected”, indicated by a green bullet
Then copy and paste the mini computers IP address into a new browser window address bar.
You need to sign into the KVM using a username and password and then sign into the mini computer “benchbot” user with another password. These 2 passwords should be provided to you privately.
To take an image from the mini-computer
Open up a browser on the mini computer and copy and paste this into address bar:
localhost:5000/image
You should see an image appear in the browser window
Flash Setup
Set up the flash with the desired settings, as settings influence the flash duration. My assumptions are:
Manual mode
1/1, 1/2+0,3-0,6 or 1/2 flash power level
Not sure about "stable color temperature" and it's impact to the frequency at which the flash can fire.. Should be tried out. We'd like a constant color temperature, but not sure what the downside is here, since it's not turned on always.
"stand by" should be turn off, or set to something like 120 min.
"Delay flash" should be turn off
Modeling lamps should be turned off
Observe the flash duration time t=0.1. This is presumably done with the "TIMES" function of the flash.
Camera Setup/Config
Turn off all auto settings.
This includes exposure times, gains, white balancing, etc.
Set exposure time to half of t0.1 from the flash. Pay attention to difference in units.
While you have a non-changing level of ambient light:
Capture a series of images with a varied camera-set delay between flash trigger and image exposure. The entire scene has to stay constant.
If the images are overexposed in this experiment, modify the aperture on the lens accordingly.
Note the delay that resulted in the brightest image and put that delay into the camera.
Color and focus calibration.
Place a color checker below the camera, preferably the big one. If the camera cannot move in the z-axis, place the color checker 15 cm above the pot soil level.
Refocus the camera to ensure that focus is accurate. This is done with the color checker by zooming in on the millimeter markers. Open up the aperture all the way and repeatedly make tiny adjustments -> image capture -> zoom in and evaluate until focus is just right.
Reset the aperture to an appropriate level based on the brightness of the image at the designated flash power.
Capture a good quality image of the colorchecker to be used for color calibration (specifically to determine the color calibration matrix used for DNG-formatting of the images)
To determine the effect of the stable color temperature, it makes sense to run a stress test with and without it at our desired flash power. That would also help answer whether the flash will bottleneck the bbot at the given power level (edited)
Protocols
Camera testing
place colorchecker card 15 cm
set the aperture to the lowest number
adjust exposure
start finding the right focus so that the milliliter scale on the colorchecker are incredibly clear, adjust by millimeter. For example here is how the scale bar should look -
after the right focus has been identified, set it using the set screw
now adjust aperture and exposure as needed
Date | Lens height above ground | Lens height above plants | Focus | Aperture | Exposure | Flash Power |
---|---|---|---|---|---|---|
2024-11-18 | 1.66 m | 21.5 | 4 | 1 | 1/32 |
Camera Settings Definitions
Setting | Description |
---|---|
Aperture | Aperture refers to the opening in a camera lens through which light passes to reach the camera sensor. It is measured in f-stops (e.g., f/1.8, f/2.8, f/5.6). Lower f-stop values (e.g., f/1.8) mean a wider aperture, allowing more light in, while higher values (e.g., f/22) narrow the opening, letting in less light. A wide aperture (low f-stop) creates a shallow depth of field, blurring the background and focusing on the subject. A narrow aperture (high f-stop) results in a deeper depth of field, keeping more of the scene in focus. |
Focus | Focus determines the sharpness of the subject in the image. When the subject is in focus, it appears sharp and clear, while elements not in focus appear blurred. Manual focus allows you to control which part of the scene is sharp. |
Exposure Time | |
Aperture and focus done manually on site
Exposure setting configured in the .txt file
Resources
SVCam
Flash
As of 2024/11/15 only NC has this flash
Lens
Linos Inspect XL 60mm (link)
Color Checker Chart
XRite ColorChecker calibration data sheet -
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